ACIDOSIS 67 



in diabetes (Van Slyke and Fitz(a), 1917), and is related to it as indi- 

 cated in Table II on p. 85. 



The Normal and Abnormal Variations in the Acid-Base 



Balance of the Blood, and the Resultant Effects 



on Physiological Functions 



When the above outlined defenses against acidification fail to respond 

 normally, or when the acid invasion is too rapid to be met, or when the 

 centers regulating the physiological portions of the mechanism become 

 either over- or undersensitive, the acid-base balance is deranged. In order 

 to recognize the characteristics of the blood conditions that result, it is 

 desirable to consider the variations that lead to or involve both alkaliniza- 

 tion and acidification, since conditions occur under which abnormality in 

 either direction may be mistaken for its opposite unless data are available 

 to furnish a consideration of all the possibilities. 



The possible variations in the acid-base balance of the blood may be 

 stated as follows: the blood bicarbonate may be high, low, or normal, and 

 in each of these conditions the pH may be high, low, or normal. There 

 are thus nine theoretically possible conditions. Only one of them is 

 normal, that in which both bicarbonate and pH are within the normal 

 limits. At the time of Van Slyke and Cullen's original paper (1917) only 

 two of the abnormal possibilities had come under clinical observation, that 

 in which bicarbonate is low, and pH normal (compensated acidosis), 

 and that in which bicarbonate is very low, and pH also low (uncompen- 

 sated acidosis). Now, however, as the result of the recent work of 

 Y. Henderson and Haggard, of Scott, of Milroy, of Collip, of Davies, 

 Haldane, and Kennaway, of Grant and Goldman, of Peters and Barr, and 

 of others, it is known that the other six abnormal possibilities can be 

 produced experimentally, and that at least some of them occur clinically. 

 For this reason, it has seemed desirable to enlarge the view presented in 

 our former paper in order to include within it these conditions. 



Representation of the Combined Variations in Blood Bicarbonate and 

 Hydrion Concentration. The blood conditions may be represented by a 

 diagram of the type used by Haldane and others to show the "CO 2 absorp- 

 tion curves" of the blood, and recently further elaborated by Straub and 

 Meier (1918) and by Haggard and Y Henderson (1919) to show also 

 the pH values. 



If we draw a curve, expressing [BHCO 3 ] values as ordinates, and 

 [H 2 CO 3 ] values as abscissae, the curve will be a slanting straight line for 

 all points corresponding to any given [BHCO 3 ] :[H 2 CO 3 ] ratio, and the 



